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� e j� e j� dS )z�Support asyncio with serial ports. EXPERIMENTAL
Posix platforms only, Python 3.4+ only.
Windows event loops can not wait for serial ports with the current
implementation. It should be possible to get that working though.
� Nc s� e Zd ZdZ� fdd�Zedd� �Zdd� Zdd � Zd
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dd� Zd:dd�Zdd� Zdd � Zd d � Zd d � Zd!d"� Zd#d$� Zd%d&� Zd'd(� Zd)d*� Zd+d,� Zd;d-d.�Zd<d0d1�Zd2d3� Z d=d4d5�Z d6d7� Z d8d9� Z � Z S )>�SerialTransportug An asyncio transport model of a serial communication channel.
A transport class is an abstraction of a communication channel.
This allows protocol implementations to be developed against the
transport abstraction without needing to know the details of the
underlying channel, such as whether it is a pipe, a socket, or
indeed a serial port.
You generally won’t instantiate a transport yourself; instead, you
will call `create_serial_connection` which will create the
transport and try to initiate the underlying communication channel,
calling you back when it succeeds.
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zSerialTransport.__init__c C s | j S )z The underlying Serial instance.)r )r r r r �serial< s zSerialTransport.serialc C s dj | d�S )NzH{self.__class__.__name__}({self._loop}, {self._protocol}, {self.serial}))r )�format)r r r r �__repr__A s zSerialTransport.__repr__c C s | j S )z2Return True if the transport is closing or closed.)r )r r r r �
is_closingD s zSerialTransport.is_closingc C s | j s| jd� dS )aD Close the transport gracefully.
Any buffered data will be written asynchronously. No more data
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After all buffered data is flushed, the protocol's
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argument.
N)r �_close)r r r r �closeH s zSerialTransport.closec C sX y| j j| j�}W n0 tjk
rB } z| j|d� W Y d d }~X nX |rT| jj|� d S )N)�exc)r �readr
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data_received)r �data�er r r � _read_readyT s zSerialTransport._read_readyc C s� | j r
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rT } z| j|d� dS d}~X nX |t|�krfdS ||d� }| j� | j j
|� | j � dS )z�Write some data to the transport.
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Fr )r r r r �
can_write_eofv s z SerialTransport.can_write_eofc C s | j � dS )u� Pause the receiving end of the transport.
No data will be passed to the protocol’s data_received() method
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N)�_remove_reader)r r r r �
pause_reading} s z SerialTransport.pause_readingc C s | j � dS )z�Resume the receiving end of the transport.
Incoming data will be passed to the protocol's data_received()
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N)r )r r r r �resume_reading� s z SerialTransport.resume_readingNc C s | j ||d� | j� dS )uL Set the high- and low-water limits for write flow control.
These two values control when call the protocol’s
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specified, the low-water limit must be less than or equal to
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)�high�lowN)r r+ )r r1 r2 r r r �set_write_buffer_limits� s z'SerialTransport.set_write_buffer_limitsc C s t tt| j��S )z�The number of bytes in the write buffer.
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)�sum�mapr( r )r r r r r% � s z%SerialTransport.get_write_buffer_sizec C s t d��d S )Nz-Serial connections do not support end-of-file)�NotImplementedError)r r r r � write_eof� s zSerialTransport.write_eofc C s | j d� dS )a. Close the transport immediately.
Pending operations will not be given opportunity to complete,
and buffered data will be lost. No more data will be received
and further writes will be ignored. The protocol's
connection_lost() method will eventually be called.
N)�_abort)r r r r �abort� s zSerialTransport.abortc C sl | j � | jkrdS | jshd| _y| jj� W n: tk
rf } z | jjd|| | jd�� W Y dd}~X nX dS )a
To be called whenever the write-buffer size increases.
Tests the current write-buffer size against the high water
mark configured for this transport. If the high water mark is
exceeded, the protocol is instructed to pause_writing().
NTz protocol.pause_writing() failed)�message� exception� transportr )r% � _high_waterr r �
pause_writing� Exceptionr �call_exception_handler)r r r r r r+ � s z%SerialTransport._maybe_pause_protocolc C sh | j rd| j� | jkrdd| _ y| jj� W n: tk
rb } z | jjd|| | jd�� W Y dd}~X nX dS )a- To be called whenever the write-buffer size decreases.
Tests the current write-buffer size against the low water
mark configured for this transport. If the write-buffer
size is below the low water mark, the protocol is
instructed that is can resume_writing().
Fz protocol.resume_writing() failed)r: r; r< r N)r r% �
_low_waterr �resume_writingr? r r@ )r r r r r �_maybe_resume_protocol� s z&SerialTransport._maybe_resume_protocolc C s� dj | j�}t|�}| jj� y| jj|�}W nR ttfk
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� dS )a� Asynchronously write buffered data.
This method is called back asynchronously as a writer
registered with the asyncio event-loop against the
underlying file descriptor for the serial port.
Should the write-buffer become empty if this method
is invoked while the transport is closing, the protocol's
connection_lost() method will be called with None as its
argument.
� z%Fatal write error on serial transportN)�joinr r( �clearr r& �BlockingIOError�InterruptedErrorr* r r r' �_remove_writerrC r �_flushedr )r r" Z num_bytesr, r r r r � _write_ready� s&
z SerialTransport._write_readyc C s. | j r*| j r*| jj| jj| j� d| _ d S )NT)r
r r Z
add_readerr �fdr$ )r r r r r s z SerialTransport._ensure_readerc C s | j r | jj| jj� d| _ d S )NF)r
r Z
remove_readerr rL )r r r r r. s z SerialTransport._remove_readerc C s. | j r*| j r*| jj| jj| j� d| _ d S )NT)r r r Z
add_writerr rL rK )r r r r r) s z SerialTransport._ensure_writerc C s | j r | jj| jj� d| _ d S )NF)r r Z
remove_writerr rL )r r r r rI s z SerialTransport._remove_writerc C sd |dkr |dkrdnd| }|dkr,|d }|| ko>dkn sTt d||f ��|| _|| _dS )z&Ensure consistent write-buffer limits.N�@ i � r z*high (%r) must be >= low (%r) must be >= 0i )�
ValueErrorr= rA )r r1 r2 r r r r s z(SerialTransport._set_write_buffer_limits� Fatal error on serial transportc C s& | j j||| | jd�� | j|� dS )z?Report a fatal error to the event-loop and abort the transport.)r: r; r< r N)r r@ r r8 )r r r: r r r r' " s z SerialTransport._fatal_errorc C s | j � dkS )z3True if the write buffer is empty, otherwise False.r )r% )r r r r rJ , s zSerialTransport._flushedc C s2 d| _ | j� | j� r.| j� | jj| j|� dS )a� Close the transport gracefully.
If the write buffer is already empty, writing will be
stopped immediately and a call to the protocol's
connection_lost() method scheduled.
If the write buffer is not already empty, the
asynchronous writing will continue, and the _write_ready
method will call this _close method again when the
buffer has been flushed completely.
TN)r r. rJ rI r r �_call_connection_lost)r r r r r r 0 s
zSerialTransport._closec C s* d| _ | j� | j� | jj| j|� dS )aP Close the transport immediately.
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and buffered data will be lost. No more data will be received
and further writes will be ignored. The protocol's
connection_lost() method will eventually be called with the
passed exception.
TN)r r. rI r r rQ )r r r r r r8 B s zSerialTransport._abortc C sH | j j� z| jj|� W d| jj� | j j� d| _ d| _d| _X dS )z�Close the connection.
Informs the protocol through connection_lost() and clears
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N)r �flushr �connection_lostr rF r r )r r r r r rQ P s
z%SerialTransport._call_connection_lost)NN)NN)rP )N)!�__name__�
__module__� __qualname__�__doc__r �propertyr r r r r$ r& r- r/ r0 r3 r% r7 r9 r+ rC rK r r. r) rI r r' rJ r r8 rQ �
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r c O s& t j||�}|� }t| ||�}||fS )N)r Zserial_for_urlr )r �protocol_factory�args�kwargsZserr r< r r r �create_serial_connectiond s r] c + s� | j dtj� �}| j dtjj�}tj||d�}tj||d�� x2tf |� fdd�d�| ��D ]\}}||fV qZW tj|� ||�}t ||��dS ) a� A wrapper for create_serial_connection() returning a (reader,
writer) pair.
The reader returned is a StreamReader instance; the writer is a
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The arguments are all the usual arguments to Serial(). Additional
optional keyword arguments are loop (to set the event loop instance
to use) and limit (to set the buffer limit passed to the
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)r< �printr Zrtsr& )r r< r r r r � s
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)rl �reprr< r )r r" r r r r! � s zOutput.data_receivedc C s t d� tj� j� d S )Nz port closed)rl ra rb �stop)r r r r r rS � s zOutput.connection_lostc C s t d� t | jj� � d S )Nz
pause writing)rl r< r% )r r r r r> � s zOutput.pause_writingc C s t | jj� � t d� d S )Nzresume writing)rl r< r% )r r r r rB � s zOutput.resume_writingN)rT rU rV r r! rS r> rB r r r r rk � s
rk z /dev/ttyUSB0i � )Zbaudrate)rW ra r Z Transportr � coroutiner] ri rT ZProtocolrk rb r �coroZrun_until_completeZ run_foreverr r r r r �<module> s Q#